Sociolinguistics and Dialectology both deal with the relationship between language and society. Both have as their raw material language variation (e.g. differences between accents and dialects). Dialectology is the `parent' discipline of some parts of sociolinguistics- those concerned with social differences in speech and the social explanation of language change. 'Traditional dialectology' was concerned with the way linguistic features vary geographically, while `modern dialectology' is interested in differences in phonological and grammatical 'systems' - bringing modern linguistic insights into the description of linguistic differences.
These dialectological matters will feed into the more `sociolinguistic' issues just mentioned - the relationship between language and social parameters, including sex, class, age, context, and the immediate influence of a person's social contacts on the way he or she speaks. The dialectological perspective on language change will be broadened to consider what happens when two languages or dialects are in contact in a community. but a more wide-ranging approach will be taken, too, and we will be covering such diverse topics as language attitudes, national language planning and bilingualism.